1. Field of the Invention
This invention relates generally to the field of semiconductor device manufacturing and, more particularly, to a method and apparatus for controlling a tool using a baseline control script.
2. Description of the Related Art
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in a continual improvement in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
Generally, a set of processing steps is performed on a lot of wafers using a variety of processing tools, including photolithography steppers, etch tools, deposition tools, polishing tools, rapid thermal processing tools, implantation tools, etc. The technologies underlying semiconductor processing tools have attracted increased attention over the last several years, resulting in substantial refinements. However, despite the advances made in this area, many of the processing tools that are currently commercially available suffer certain deficiencies. In particular, such tools often lack advanced process data monitoring capabilities, such as the ability to provide historical parametric data in a user-friendly format, as well as event logging, real-time graphical display of both current processing parameters and the processing parameters of the entire run, and remote, i.e., local site and worldwide, monitoring. These deficiencies can engender nonoptimal control of critical processing parameters, such as throughput, accuracy, stability and repeatability, processing temperatures, mechanical tool parameters, and the like. This variability manifests itself as within-run disparities, run-to-run disparities and tool-to-tool disparities that can propagate into deviations in product quality and performance, whereas an ideal monitoring and diagnostics system for such tools would provide a means of monitoring this variability, as well as providing means for optimizing control of critical parameters.
One technique for improving the operation of a semiconductor processing line includes using a factory wide control system to automatically control the operation of the various processing tools. The manufacturing tools communicate with a manufacturing framework or a network of processing modules. Each manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface which facilitates communications between the manufacturing tool and the manufacturing framework. The machine interface can generally be part of an advanced process control (APC) system. The APC system initiates a control script based upon a manufacturing model, which can be a software program that automatically retrieves the data needed to execute a manufacturing process. Often, semiconductor devices are staged through multiple manufacturing tools for multiple processes, generating data relating to the quality of the processed semiconductor devices.
During the fabrication process, various events may take place that affect the performance of the devices being fabricated. That is, variations in the fabrication process steps result in device performance variations. Factors, such as feature critical dimensions, doping levels, contact resistance, particle contamination, etc., all may potentially affect the end performance of the device. Various tools in the processing line are controlled in accordance with performance models to reduce processing variation. Commonly controlled tools include photolithography steppers, polishing tools, etching tools, and deposition tools. Pre-processing and/or post-processing metrology data is supplied to process controllers for the tools. Operating recipe parameters, such as processing time, are calculated by the process controllers based on the performance model and the metrology information to attempt to achieve post-processing results as close to a target value as possible. Reducing variation in this manner leads to increased throughput, reduced cost, higher device performance, etc., all of which equate to increased profitability.
Configuration control and efficiency issues are prevalent in a distributed computing environment, such as a factory-wide APC system. Typically, there are numerous software developers writing control code to construct the process controllers. One particular developer may work extensively developing controllers of a certain type. It is common for each developer to have a unique programming style, and to rely on routines that they have created themselves. For example, each developer may have a set of routines for interfacing with databases or other entities within the APC framework and for performing various math functions and basic utility functions.
One problem associated with such an arrangement is that there is little consistency between process control scripts. The large number of custom scripts also presents a configuration control problem and an efficiency problem. Developers may spend considerable time duplicating code that has already been developed, perhaps for a different type of process controller that a different developer has created. Debugging non-standardized code is also more time-consuming and further reduces efficiency.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
One aspect of the present invention is seen in a method for controlling a manufacturing system. The method includes processing workpieces in a plurality of tools; initiating a baseline control script for a selected tool of the plurality of tools; providing context information for the baseline control script; determining a tool type based on the context information; selecting a control routine for the selected tool based on the tool type; and executing the control routine to generate a control action for the selected tool.
Another aspect of the present invention is seen in a manufacturing system including a plurality of tools adapted to process workpieces, a control execution manager, and a control executor. The control execution manager is adapted to initiate a baseline control script for a selected tool of the plurality of tools and provide context information for the baseline control script. The control executor is adapted to execute the baseline control script, determine a tool type based on the context information, select a control routine for the selected tool based on the tool type, and execute the control routine to generate a control action for the selected tool.